A screen roller of an inking unit for a rotary printing press is disclosed in EP 1 044 110 B1 and in U.S. Pat. No. 6,439,116, which is a member of the same patent family. A surface area of the screen roller has endless or helix-like grooves or cross-hatchings which are arranged at an angle of inclination or an angle of rise in a range of between 0° and plus/minus 20°. The raster frequency of these grooves lies between 100 and 400 grooves per centimeter.
Methods are known from WO 03/045694 A1 and from WO 03/045695 A1, in which the tack of a printing ink on a rotating component is maintained substantially constant within a temperature range of 22° C. to 50° C. by heat control of a rotating component of a printing group, which rotating component acts together with the printing ink. The tack of the printing ink is a function of the temperature on the surface area of the rotating component and of the production speed of the latter. Such printing ink is used, in particular, in a printing group for waterless printing, and preferably in a printing group for newspaper printing.
A short inking unit of a rotary printing press is known from WO 01/87036 A2. A screen roller which processes pasty printing ink, in particular printing ink of a viscosity of greater than 9000 mPa*s, is provided. A raster of the screen roller has a ratio of at least 0.5, and in particular greater than 0.8, with respect to a raster of a printing forme on a forme cylinder which is also arranged in the rotary printing press.
The article “Wasserloser Offsetdruck—Alternative für wirtschaftliche, hochwertige und umweltverträgliche Druckproduktion” or Waterless Offset Printing—Alternatives for Efficient, High-quality and Environmentally Friendly Print Production, which appears in the trade journal “Deutscher Drucker,” The German Printer, no. 7 of Feb. 16, 1995, pp. W6, 8, 10, 12, discusses that in waterless offset printing special, relatively tacky printing inks are used. Optimal printing results are achieved by a temperature control of inking unit rollers, or by a cooling of the forme cylinder. A constant surface temperature of the printing formes and the rubber blankets is attempted to be maintained.